Fixes #432 (read syscall length is halved for stdin)

[iridescent1024]

Summary

This PR fixes a bug where read syscalls on stdin process only half the buffer provided.

Problem

When a syscall requests N bytes, RIPES currently processes only N/2 bytes.

Root cause

The read loop reduced lengthRequested on each iteration while growing myBuffer. Since the loop condition was myBuffer.size() < lengthRequested, both values converged toward the midpoint, causing the loop to terminate after processing only half the requested characters.

Fix

Removed the decrement of lengthRequested.

Testing

• Verified with a minimal RISC-V program that requests a fixed number of characters.
• Confirmed that the full requested input is now processed correctly.

Related issue

Fixes #432